The role of Adenovirus 2 coded and induced proteins in the determination of the tumorigenic potential of a transformed cell is virtually unknown at this time. This proposal will study the effects of these proteins on the tumorigenic potential by identifying those viral or cellular proteins that plan a role in the induction of cellular or humoral immune responses in the host. The ultimate goal is to determine which viral gene products (if any) are controlling the expression of these Ad2 transformed cell surface antigens. We will identify the transformed cell surface antigens that are present on Adenovirus 2 transformed cell lines that differ in their tumorigenic potantial, determining whether they are viral or cellular antigens. Specific defined antisera will be produced against the individual cell lines and used to select cells that are no longer expressing these particular antigens. The selected cells will then be characterized for their resistance to cytotoxic T-cells and for their retention of the viral DNA integration patterns. A series of defined mutants for various cell surface antigens (greater than 1 for each antigen) will then be developed for further use in more detailed studies. It is anticipated that this well defined system will provie to be a good working model for determining the role of different surface antigens on malignant growth characteristics.